What counts as a duplicate line?
- Exact match. A line is a duplicate when the whole line matches an earlier line — not just one word inside it. “seo tool” and “seo tools” are two different lines.
- Case. With case-sensitive matching (the default), “Apple” and “apple” are different lines. With “Ignore case” on, only the first one is kept, with its original capitalisation.
- Whitespace. With “Trim whitespace” on, a line with extra spaces around it matches the same line without them, but the kept copy still shows the original spacing of its first occurrence.
- Blank lines. Empty lines are lines too. With “Remove empty lines” on, every blank line is dropped. With it off, the first blank line is kept like any other line.
- Order. Unlike the command-line
uniq tool, which only catches repeats next to each other, this tool finds repeats anywhere in the list — even hundreds of lines apart — and keeps your original order unless you ask for a sort.
Input:
content ideas
Content Ideas
blog topics
content ideas
blog topics
keyword research
With the default settings (trim on, case-sensitive):
content ideas
Content Ideas
blog topics
keyword research
“blog topics” drops out because, with trim on, it matches
“ blog topics”. Turn “Ignore case” on and “Content Ideas”
also drops out, because it matches “content ideas”.
Remove duplicate lines — FAQ
How do I get rid of duplicate lines?
Paste your list into the box above, one item per line. The clean list appears instantly, with every repeated line removed and only the first copy kept. Copy the result or download it as a .txt file. Nothing is uploaded anywhere — the whole check runs in your browser.
Does it keep the original order of my list?
Yes. By default the first occurrence of each line stays exactly where it was, and later repeats are removed without shifting anything else. If you want the result alphabetised instead, choose “Sort A to Z” or “Sort Z to A” in the output order menu.
What is the difference between case-sensitive and case-insensitive matching?
Case-sensitive matching treats “Apple” and “apple” as two different lines, and both are kept. Case-insensitive matching treats them as the same line and keeps only the first one, with its original capitalisation. Use case-sensitive matching for code, file paths and database IDs, and case-insensitive matching for email lists, names and keyword lists.
Do spaces at the start or end of a line matter?
Only if you want them to. With “Trim whitespace before comparing” switched on, leading and trailing spaces are ignored when deciding whether two lines match, so “ keyword ” and “keyword” count as duplicates. The line that is kept still shows the spacing of its first occurrence.
Can I remove duplicate words instead of duplicate lines?
No — this tool works line by line, so each line is treated as one item and the words inside it are left untouched. If the same word appears on different lines, those lines are only duplicates when the whole lines match. For counting how often words appear in a text, use our Word Counter.
Can I remove duplicate rows from a spreadsheet?
For one column or one exported list, yes: copy that column, paste it here, dedupe it, and paste the clean list back. For a full multi-column spreadsheet, use your spreadsheet app’s own remove-duplicates feature instead, because it can compare whole rows across columns — this tool compares one line at a time.
How do I remove duplicate lines and blank lines at the same time?
Leave “Remove empty lines” switched on (it is on by default). Every blank line is dropped along with the duplicate lines, and the count of blank lines removed shows in the statistics above the output.
Is my list private? Is anything uploaded?
Yes, it is private. All processing happens in your browser with JavaScript, and your text is never sent to a server. That makes the tool safe for email lists, customer data and internal logs, and it works the same way whether your list has ten lines or ten thousand.
Keyword listsEmail listsURLsLog filesCSV exportsDedupe
More free text tools: Word Counter · Case Converter · Fancy Text Generator · Strikethrough Text Generator · Underline Text Generator · Reverse Text Generator · Invisible Text Generator
Everything runs in your browser — nothing you paste is sent anywhere, and no account is needed.
